Wave guide



1958 R. L. WlLLlSTON 2,822,524

WAVE GUIDE Filed 0612. 25, 1954 Robert L. Williston INVENTOR.

United States Patent O WAVE GUIDE Robert L. Williston, Milford, N. H., assignor, by mesne assignments, to Sanders Associates, Inc., Nashua, N. H., a corporation of Delaware The present invention relates to high frequency trans-- mission lines. More particularly, this invention relates to dielectric filled wave guides as used in the transmission of high frequency electromagnetic energy.

Wave guide transmission lines such as are used in the prior art, have proved to be expensive, heavy and bulky in assembly. Past efforts in the design of such wave guides having a relatively thin conductive boundary have generally proved unsuccessful.

It is therefor an object of the present invention to pro vide an improved wave guide transmission line which is light, compact and may be assembled with facility.

A further object of the invention is to provide an im proved method of manufacturing such a transmission line.

Other and further objects of the invention will be apparent from the following description of a preferred embodiment, taken in connection with the accompanying drawing.

In accordance with the present invention there is provided a high-frequency wave guide. The transmission line has a conductive pattern of such weak mechanical structure that it is incapable of self-maintaining its configuration and has terminations providing an irregular pattern. The line comprises a dielectric material formed in a predetermined irregular configuration and conductive material chemically deposited on selective surfaces surrounding the dielectric material to provide a continuous boundary and forming a wave guide of irregular shape and having a pattern of irregular terminations. The wave guide is encapsulated with a resin which is transparent to visible light to provide the wave guide component in a regular plane configuration having substantial rigidity and enabling ready location of the wave guide termination, as well as adapting the component for assembly as a modular component.

In the accompanying drawings:

Fig. 1 is a plan view of a wave guide component embodying the present invention;

Fig. 2 is a perspective view of the embodiment shown in Fig. l; and

Fig. 3 is a cross-sectional view of the embodiment of Fig. l of the component taken along the line III-III and vertically expanded.

Referring now to the drawings, a sheet of polystyrene 1, having a predetermined form, such as shown, suitable for the wave guide, is molded in the desired configuration. A conductive paint 2, such as an air-drying liquid silver paint (as manufactured by E. I. du Pont de Nemours & Company) is applied, preferably by spraying, to the polystyrene form. The silver 3 is applied, for example, by electroplating, to the painted surface of the form 1. This silver is preferably of a thickness of .002 of an inch, and provides a conductive pattern of such weak mechanical structure that it is incapable of self-maintaining its configuration. The silver forms the boundary of a dielectric filled wave guide. Energy is transmitted by the guide between the inside surfaces of the silver. In this condition the silver is undesirably susceptible to being removed from the polystyrene even with careful handling. By encapsulating the wave guide element with a transparent epoxy resin 4, such as Hysol 6020 (as manufactured by Houghton Laboratories), the wave guide is fabricated in the form of a fiat, substantially rigid sheet, with the wave guide structure per se clearly visible. The particular wave guide component illustrated is a high frequency directional power splitter known in the art as a hybrid ring.

There are, of course, many standard processes available for applying a conductive material such as silver, copper or aluminum to a dielectric material. Among these are evaporation-condensation techniques, electrodeposition and chemical deposition. The dielectric material may be pre-forrned by injection molding, cold stamping and so forth.

This process permits the fabrication of wave guide components having a depth of conductive material that is as thin as may be desired, for example, on the order of molecular layers thick and therefor is incapable of selfmaintaining its configuration. In ordinary practice, the thickness of the material need only be a hundred microns. The encapsulating material provides the desired substantial rigidity for the component.

The form factors attainable with components embodying the present invention greatly enhance the economy and facility of the manufacture and assembly of high frequency transmission line components. It will be apparent that the device of the present invention readily lends itself to arrangements of the components in planar assemblies which may be extraordinarily compact.

While there has been hereinbefore described what is at present considered a preferred embodiment of the present invention, it will be apparent that many and various changes and modifications may be made with respect to the embodiment illustrated, without departing from the spirit of the invention. it will be understood, therefore, that all those changes and modifications as fall fairly within the scope of the present invention, as defined in the appended claims, are to be considered as a part of the present invention.

What is claimed is:

1. A high frequency wave guide transmission line having a conductive pattern of such weak mechanical structure that it is incapable of self-maintaining its configuration and having terminations providing an irregular pattern comprising: a dielectric material formed in a predetermined irregular configuration; conductive material chemically deposited on selected surfaces surrounding said dielectric material to provide a continuous boundary and forming a wave guide of irregular shape and having a pattern of irregular terminations; and a resin transparent to visible light encapsulating said wave guide to provide said wave guide component in a regular plane configuration having substantial rigidity and enabling ready location of the wave guide termination as well as adapting the component for assembly as a modular component.

2. A high frequency wave guide transmission line having a silver pattern of such weak mechanical structure that it is incapable of self-maintaining its configuration and having terminations providing an irregular pattern comprising: a polystyrene material transparent to visible light and formed in a predetermined irregular configuration; silver material chemically deposited on selected surfaces surrounding said transparent polystyrene material to provide a continuous boundary and forming a wave guide of irregular shape and having a pattern of irregular terminations; and a transparent polystyrene material encapsulating said wave guide to provide said wave guide component in a regular plane configuration having substantial rigidity and enabling ready location of the wave guide termination as well as adapting the component for assembly as a modular component.

References Cited in the file of this patent UNITED STATES PATENTS FOREIGN PATENTS France June 24, 1953 OTHER REFERENCES Barrett: Etched Sheets Serve as Microwave Components, Electronics, June 1952, pages 114118. Copy in Patent Office Library and 333-84M.

Plastiscope, Modern Plastics, June 1952, page 210. 

